Recently, I worked on a sample library for game developers named “107 Free Retro Game Sounds”. As the name might suggest, it contains sound effects and music that both bring back the feeling of retro games.
Before I started to design those sounds, I had to ask myself a certain question: Why do retro games sound so retro? To answer this question, I had to analyse the audio chips of early game devices like the Gameboy, the Atari or the Mattel Intellivision. Although, these systems differ a little bit, they have some similarities concerning their sound generation. With that in mind, I developed a guideline on how to emulate the sound of those systems. Moreover, I was able to recreate any sound of my favourite games very easily. Watch this playlist, to see and hear what I mean:
Do I have your attention? Let me reveal the four magic tips which will help you to sound retro:
Tip #1: Keep it simple!
Usually, when I design synthesizer presets, I want them to be huge and powerful. Therefore, I use all oscillators with various complex waveforms plus the white noise section. It goes on with multiple voices, detuning, pitch envelopes, filter envelopes, stereo widening, delay, reverb, saturation… For designing retro sounds, you have to do exactly the opposite: Keep it simple! This is due to the functionality of old sound cards. They had only one source (i.e. one oscillator) with only very few waveforms (pulse, square, triangle, noise). There were no such things as effects like delay or reverb because those would have been too CPU-intensive. Even filters weren’t there. Forget about additional envelopes! Just your very basic amp envelope. In sum: Choose one oscillator with a very simple waveform and shape it with your amp envelope.
Nonetheless, there is a way to design movement within your sound. And this brings us to the next tip…
Tip #2: Use arpeggios!
Rather than using LFOs or pitch envelopes, you have to draw in very short notes into your MIDI editor. Use 16th or 32th notes that move upwards or downwards. This creates the sound which you might associate with Super Mario jumping through crazy 8-bit worlds. With different rhythms and melodies you are able to design sounds which fit to any motion.
Why does this technique sound so retro? Well, it’s because of the way it simulates those old sound chips. They generated a series of tones, instead of generating one tone and modulating it.
Tip #3: Be square!
Remember what I said in tip #1 about the waveforms?There’s even one of them which is so much retro that it could rope you into a 2D-world. Literally speaking. And this waveform is the square wave. Have you ever played some high notes on a synthesizer with only one square wave oscillator turned on? It instantly seems to tell a story of an 8-bit hero in an 8-bit world.
Again, why does that sound so much retro? The reason for this is that a sound file with a low resolution is pretty much angular-shaped, if you take a closer look at the waveform. Zoom in and you know what I mean. It looks just like a pulse wave or a square wave. (Note: A square wave is a pulse wave with a width of 50:50.)
Tip #4: Crush it down!
As I said, retro game sound design is all about downsampling and a low bit resolution. The first sound cards mostly had an 8-bit resolution and a sampling rate of 22.050 Hz.
What you can do is the following: Crush down your signal at the end of the chain. Therefore, you could use plugins like a bitcrusher. Or you could export your file in a low resolution (8 bit, 22.050 Hz) and then import it to your project. Then you can export it again into the desired format (mp3 or wav).
There’s another way to simulate the low resolution. This method involves an EQ. I know, I told you to keep it simple, but we’ll use the EQ creatively to emulate the effect of the Nyquist theorem. For this, you have to create a highcut filter at around 10 kHz. Additionally, You can use a lowcut at around 100 Hz to simulate the lack of low end which is typical for the sound of retro systems.
Want to apply your learnings?
These four tips are a rough guideline to retro game sound design. If you want to create a particular sound, here’s a video that teaches you how to design the Pacman “Waka Waka” sound: